Experiment Tunka : High energy cosmic rays and Gamma-ray astronomy L.A.Kuzmichev (MSU SINP) on behalf of Tunka Collaboration Napoli 2013

Tunka Collaboration S.F.Beregnev, S.N.Epimakhov, N.N. Kalmykov, N.I.KarpovE.E. Korosteleva, V.A. Kozhin, L.A. Kuzmichev, M.I. Panasyuk, E.G.Popova, V.V. Prosin, A.A. Silaev, A.A. Silaev(ju), A.V. Skurikhin, L.G.Sveshnikova I.V. Yashin, Skobeltsyn Institute of Nucl. Phys. of Moscow State University, Moscow, Russia; N.M. Budnev, O.A. Chvalaev, O.A. Gress, A.V.Dyachok, E.N.Konstantinov, A.V.Korobchebko, R.R. Mirgazov, L.V. Pan’kov, A.L.Pahorukov, Yu.A. Semeney, A.V. Zagorodnikov Institute of Applied Phys. of Irkutsk State University, Irkutsk, Russia; B.K. Lubsandorzhiev, B.A. Shaibonov(ju) , N.B. Lubsandorzhiev Institute for Nucl. Res. of Russian Academy of Sciences, Moscow, Russia; V.S. Ptuskin IZMIRAN, Troitsk, Moscow Region, Russia; Ch. Spiering, R. Wischnewski DESY-Zeuthen, Zeuthen, Germany; A.Chiavassa Dip. di Fisica Universita' di Torino and INFN, Torino, Italy. A.Haungs, F. Schroeder, R.Hiller Karlsruhe Institute of Technology, Karlsruhe, Germany D.Horns, M.Tlucziykont , R.Nachtigall, M.Kunnas Hamburg University, Germany

OUTLINE 1. Tunka-133. 2. Energy spectrum. 3. Mass composition 4. Plan for the Tunka-133 upgrading. 5. Low energy extension : Tunka-HiSCORE project.

Accuracy: core location ~ 10 m energy resolution ~ 15% 1 km Tunka-133 EAS Cherenkov array – 175 optical detectors on the 3 km2 Energy threshold ~ 1015 eV Accuracy: core location ~ 10 m energy resolution ~ 15%  Xmax < 25 g∙cm-2

Scientific aims Search for Acceleration Limit of Galactic Sources ( transition from galactic to extragalactic CR) Study of a new methods of EAS registration Low energy extension: Multi-TeV gamma-ray astronomy and CR in energy range 100 TeV - 5 PeV

7 detectors in each cluster Tunka-133: 19 clusters, 7 detectors in each cluster Optical cable DAQ center Cluster Electronic box PMT EMI 9350 Ø 20 cm 4 channel FADC boards 200 MHz, 12 bit

Experimental data fitted with LDF Using of Cherenkov Light Lateral Distribution Function (LDF) for the Reconstruction of EAS Parameters LDF from CORSIKA Q(R) = F(R, p) (only one parameter) Experimental data fitted with LDF light flux at core distance 200 m – Q200  Energy P = Q(100)/Q(200) Xmax steepness of LDF

Energy reconstruction E = A (Q200) g Density of Cherenkov light at core distance of 200 m For 1016 – 1018 eV (CORSIKA): g = 0.94±0.01

Absolute energy calibration : The QUEST experiment ( Cherenkov detectors at EAS-TOP) Integral spectrum σsys(E) = 8% p Normalization point for Tunka-133 P – steepness of LDF (Lateral Distribution Function)

Three seasons of array operation 2009 - 2010 :286 hours of good weather . 2010 – 2011: 305 hours of good weather. 2011 – 2012: 380 hours of good weather 6106 events with energy 1015 эВ. Trigger counting rate during one night . 50 detectors  1016 eV 10 events during every night with number of hitted detectors more than 100. Distribution of the number of hitted clusters in one event.

IN-events: Core position inside circle: R < 450m Zenith angle < 45° 2009-2012 >1016 eV: 63490 >1017 eV: 605 OUT- events: R <800 m > 1017 eV: 1900 800 m 450m

Shower front Tns T ns = (R+200/R0 )2 ×3.3 ns

WDF – width distant function ADF WDF LDF ADF – amplitude distant function is used for core location

1900 events > 1017 eV

Second knee γ~ 3.0 γ~ 3.3 ~3 ·1017 eV

σsys(E) = 8% At E= 6 1015 eV From QUEST experiment σsys(E) = 15% At 1018 eV due to uncertainty in g

Energy Spectrum

Mean Depth of EAS maximum Xmax g·cm-2 Mean logarithm of primary mass. PRELIMINARY

Conclusions 1. The spectrum in the energy range of 1016 to 1018 eV cannot be fitted with single power law index 3.21 ±0.01 (6·1015 – 2·1016 eV) 2.97 ±0.01 (2·1016 – 1017 eV) 3.30 ± 0.1 (3 ·1017 – 1018 eV) There is an indication on the second knee at ~3·1017 eV 3. Tunka spectrum = K-Gr spectrum inside energy reconstruction systematics. The key question – to increase accuracy of absolute energy calibration. Is it possible to have 5% accuracy? 4. More statistics is needed at the energy range of 1017 – 1018 eV The array will continue data taking for another 4-5 seasons. 5. Primary mass composition changes from the light (He) at the knee to the heavy at 3·1016 eV. The mass composition is heavy till at least 1017 eV. More statistics is needed in the energy range of 1017 – 1018 eV

Plan for upgrading Net of radio antennae Tunka-REX ( Radio Extension) Deployment of Grande stintilator detectors - Cross calibration of Cherenkov light and fluorescent light methods. Low energy extension – Tunka –HiSCORE

Tunka : 2013 -2014 Grande-station ( now in Moscow) HiSCORE

Registration of radio signals from EAS Short Aperiodic Loaded Loop Antenna (SALLA) (A.Haungs et al. Institute fur Kernphysick, Forschungszentrum, Karslruhe, Germany 20 antennas was installed in autumn 2012 Antennas are connected to the free FADC channels of Tunka-133 cluster electronics

Absolute energy calibration experiment Absolute energy calibration experiment. Repeating the “QUEST” at 1016 -1017 eV Lg (Ne / E, Tev) -P -Fe Zenith-angle: 0º -45º Energy: 1016 – 1017 eV 20 scintillation counters, 10 m2 2000 events with E >3·1016 eV per season p P – steepness of LDF

Cross calibration of Cherenkov light and fluorescent light methods. Image detector from TUS experiment S= 2 -10 м2 Field of view ± 7 deg 7-10 km

A wide-angle gamma observatory Тunka-HiSCORE A wide-angle gamma observatory HiSCORE stands for Hundred*i Square-km Cosmic Origin Explorer

Main Topics Gamma-ray Astronomy Charged cosmic ray physics   Gamma-ray Astronomy Search for the PeVatrons. VHE spectra of known sources: where do they stop? Absorption in IRF and CMB. Diffuse emission: Galactic plane, Local supercluster. Charged cosmic ray physics Energy spectrum and mass composition from 1014 to1018 eV. 108 events (in 1 km2 array) with energy > 1014 eV per one season (400 hours). Particle physics Axion/photon conversion. Hidden photon/photon oscillations. Lorentz invariance violation. pp cross-section measurement. Quark-gluon plasma.

What we can see with 1 km2 array (short list) Name RA degrees Decl Flux F at 1 TeV, 10-12cm-2 s1TeV-1 Г Flux F at 35 TeV, 10-17cm-2 s-1TeV-1 (from Milagro) Time of observation per one year (х 0.5- weater factor) Number of events per one season E> 20 TeV Tycho SNR (J0025+641) 6.359 64.13 0.17 ±0.05 Г=1.95 ±0.5 236h 88 Crab 83.6329 22.0145 32.6 ±.9.0 Г=2.6 ±0.3 162.6 ±9.4 110h, 680 SNR IC443 (MAGIC J0616+225) 94.1792 22.5300 0.58 ±0.12 Г=3.1 ±0.30 28.8 ±9.5 112h, 2 –(from MAGIC) 50 ( from Milagro) Geminga MGRO C3 PSR 98.50 17.76 37.7 ±10.7 102h, 80 M82 (Starburst Galaxy) 148.7 69.7 0.25 ±0.12 Г=2.5 ±0.6±0.2 325h, 22 Mkn 421 (BL, z=0.031 Variable ) 166.114 38.2088 50-200 Г=2.0-2.6 140h 20 - 1000 SNR 106.6+2.7 (J2229.0+6114) 337.26 61.34 1.42 ±0.33 ±0.41 Г=2.29 ±0.33 ±0.30 70.9 ±10.8 167h 140 ( from VERITAS 235 ( from Milagro) Cas A (SNR, G111.7-2.1)[6] 350.853 58.8154 1.26 ±0.18 Г=2.61 ±0.24±0.2 177h 40 CTA_1(SNR,PWN) 1.5 72.8 1.3 Г=2.3 266 h 200

Methodical approaches for 3 stages Shower front and LDFsampling technique (at the first stages). Angular resolution – 0.1 deg, Xmax measurement for hadron rejection. Using of small mirrors net with cheap matrix of PMTs for imaging technique. 3. Using of large area muon detectors for hadron rejection.

Tunka-HiSCORE – 1 km2 stage 1 9352KB 8’’, ET

Tunka-HiSCORE – 1km2 stage 2 12’’ Hamamatsu 300 m 2 m 2 mirror, ±7º FOV, No image

Tunka-HiSCORE – 1km2 stage 3 12’’ Hamamatsu 300 m Installing of PMTs matrix, Image techniques 2 m 2 mirror, ±7º FOV,

After October 2012: 3 optical stations for common operation with Tunka-133

200 m New station 150 m

Calibration light source 4 PMTs Station Electronics

Thank you

all-particle spectrum and composition of cosmic rays <lnA> based on <Xmax>; data from Hoerandel 2007